Numerical analysis of blast-induced anisotropic rock damage

Bong-Ki Park; Kook-Hwan Cho; In-Mo* Lee

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2004 Vol.6, Issue 4 Preview Page Next Page

Numerical analysis of blast-induced anisotropic rock damage 터발파압력에 기인한 이방성 암반손상의 수치해석적 분석

31 December 2004. pp. 291-302

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Abstract

Blast -induced anisotropic rock damage around a blast-hole was analyzed by a using numerical method with user-defined subroutine based on continuum damage mechanics. Anisotropic blasting pressure was evaluated by applying anisotropic rock characteristics to analytical solution which is a function of explosive and rock properties. Anisotropic rock damage was evaluated by applying the proposed anisotropic blasting pressure. Blast-induced isotropic rock damage was also analyzed. User-defined subroutines to solve anisotropic and isotropic damage model were coded. Initial rock damages in natural rock were considered in anisotropic and isotropic damage models. Blasting pressure and elastic modulus of rock were major influential parameters from parametric analysis results of isotropic rock damage. From the results of anisotropic rock damage analysis, blasting pressure was the most influential parameter. Anisotropic rock damage area in horizontal direction was approximately 34% larger and about 12% smaller in vertical direction comparing with isotropic rock damage area. Isotropic rock damage area under fully coupled charge condition was around 30 times larger than that under decoupled charge condition. Blasting pressure under fully coupled charge condition was estimated to be more than 10 times larger than that of decoupled charge condition.

Keywords

Anisotropic blasting pressure

anisotropic rock damage

anisotropic damage models

parametric analysis

발파압력이 발파공 주위 암반에 발생시키는 암반손상을 연속체 손상역학과 사용자 부프로그램을 이용한 수치해석을 통하여 분석하였다. 암반의 이방성 특성을 적용한 이방성 발파압력을 산출하였으며, 이를 이용하여 이방성 암반손상을 분석하였다. 또한 등방성 암반손상에 대해서도 분석하였다. 자연 암반이 가지고 있는 초기손상을 함께 고려하여 암반손상을 분석하였다. 등방성 암반손상의 매개변수 분석결과, 발파압력과 탄성계수가 암반손상에 가장 크게 영향을 미쳤다. 또한 이방성 암반손상의 매개변수 분석결과, 발파압력이 이방성 암반손상에 가장 크게 영향을 미쳤으나 탄성계수는 이방성 암반손상에 크게 영향을 미치지 않음을 알 수 있었다. 등방성과 이방성 암반손상을 등방성 암반손상과 비교한 결과, 이방성 암반의 수평방향 암반손상이 약 34% 증가 하였고 수직방향은 12% 감소하는 결과를 얻을 수 있었다. 등방성 암반에 대한 밀장전 조건과 디커플링장전 조건하에 발파로 인한 암반손상을 비교한 결과, 밀장전 조건의 암반손상이 디커플링장전 조건보다 약 30배 정도 크게 나타났으며, 밀장전 조건의 발파압력은 디커플링장전 조건보다 10배 이상 큼을 알 수 있었다.

키워드

이방성 발파압력

이방성 암반손상

이방성 손상 모델

매개변수 분석

References

1. Attewell, P. B.(1970), “Triaxial Anisotropy of Wave Velocity and Elastic Moduli in Slate and Their Axial Concordance with Fabric and Tectonic Symmetry”, Int. J. Rock Mech. Min. Sci., Vol. 7, pp. 193-207.

2. Brinkman, J. R. (1987), “Separating Shock Wave and Gas Expansion Breakage Mechanical”, 2nd Int. Symp. on Rock Fragmentation by Blasting, pp. 6-15.

3. Grady, D. E., and Kipp, M. E. (1980), “Continuum Modeling of Explosive Fracture in Oil Shale”, Int. J. Rock Mech. Min Sci & Geomech Abstr. Vol. 17, pp. 147-157.

4. Hao, H., Wu, C., and Zhou, Y .(2002), “Numerical Analysis of Blast-Induced Stress Waves in a Rock Mass with Anisotropic Continuum Damage Models. Part 1: Equivalent Material Property Approach”, Rock Mech. Rock Engng. 35(2), pp. 79-94.

5. Hao, H., Wu, C., and Zhou, Y. (2002), “Numerical Analysis of Blast-Induced Stress Waves in a Rock Mass with Anisotropic Continuum Damage Models. Part 2: Stochastic Approach”, Rock Mech. Rock Engng. 35(2), pp. 79-94.

6. Hibbitt, Karlsson, and Sorensen (2001), “ABAQUS/ Explicit (version 6.2) User's Manual”.

7. Kawamoto. T., Ichikawa, Y., and Kyoya, T. (1988), “Deformation and fracturing behaviour of dis-continuous rock mass and damage mechanics theory”. Int. J. Number. Anal. Met. Geomech. 12, pp. 1-30.

8. Kyoya, T., Ichikawa, Y., and Kawamoto, T. (1985), “a Damage Mechanics Theory for Discontinuous Rock Mass”, Proc. 5th Int. Conf. Num. Method in Geomech., Nagoya, Japan, pp. 469-480.

9. Liu, L., and Katsabanis, P. D. (1997), “Develop-ment of a continuum damage model for blasting analysis”, Int. J. Rock Mech. Min. Sci. Vol. 34, No. 2, pp. 217-231.

10. Murakami, S. (1983), “Notion of Continuum Damage Mechanics and Its Application to Anisotropic Creep Damage Theory”, J. Engn. Mater. and Tech. 105, pp. 99-105.

11. Panov, S. I., Sapegin, D. D., and Khrapkov, A. A. (1970), “Some Special Featires of Deformability of Rock Masses Adjoining a Gallery”, Proc. 2nd Int. Cong. Int. Soc. Rock Mech. Belgrade, Vol.1, pp.485-490.

12. Paul, B (1960), “Prediction of Elastic Constants of Multiphase Materials”, Trans. A.I.M.E., Vol. 218, pp. 36-41.

13. Ramana. Y. V., and Venkatanarayana, B. (1973), “Laboratory Studies on Kolar Rocks”, Int. J. Rock Mech. Min. Sci. & Geomech. Abstr., Vol. 10, pp. 465-489.

14. Shockey, D. A., Curran, D. R., Seaman, L., “Rosenberg, J. T., and Petersen, C. F. (1974), : Fragmentation of Rock under Dynamic Loads”,

Int. J. Rock Mech. Min. Sci. & Geomech. Abstr. 11. pp. 303-317.

15. Simha, K. R. Y., Fourney W. L., and Dick R. D. (1987), “An investigation of the usefulness of stemming in crater blasting”, 2nd International Symposium on Rock Fragmentation by Blasting, Keystone, Colorado, 23-27 pp. 591-599.

16. Valliappan, S., and Wang, Y. C. (1994), “Advances in Computational Mechanics Applied to Wave Pro-pagation Problem”, Computer Methods and Advances in Geomechanics, pp. 347-360.

17. Wohua, Z. and Valliappan, S. (1990), “Analysis of Random Anisotropic Damage Mechanics Problems of Rock Mass: Part 2-Statistical Estimation”, Rock Mech. Rock Engng. 23, pp. 241-259.

18. Wu, C. Hao, H., and Zhau, Y. (2001), “Statistical Analysis of Anisotropic Damage of th Bukit Timah Granite”, Rock Mech. Rock Engrg. 34(1) pp. 23- 38.

19. Wu, C., Hao, H., and Zhau, Y. (2003), “Distinctive and Fuzzy Failure Probability Analysis of and An-isotropic Rock Mass to Explosion Load”, Inter-national Journal for Numerical Methods in Eng-ineering, 56, pp. 767-786.

20. Yang, R., Bawden, W. F., and Katsabanis, P. D. (1996), “A New Constitutive Model for Blast Damage.” Int. J. Rock Mech. Min. Sci & Geomech. Abstr. Vol 33, No.3, pp. 245-254.

Information

Publisher :Korean Tunneling and Underground Space Association
Publisher(Ko) :한국터널지하공간학회
Journal Title :Journal of Korean Tunnelling and Underground Space Association
Journal Title(Ko) :한국터널지하공간학회 논문집
Volume : 6
No :4
Pages :291-302

Journal of Korean Tunnelling and Underground Space Association ISSN:2233-8292(Print) 2287-4747(Online) 한국터널지하공간학회 논문집

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